1. Technical Field
The present invention relates to an electronic board, a method of manufacturing the electronic board, and an electronic device.
2. Related Art
Electronic devices such as mobile telephones and personal computers have mounted therein a semiconductor chip (electronic board) whereon an electronic circuit is formed. Such a semiconductor chip is used with passive elements such as resistors, inductors and capacitors. Japanese Unexamined Patent Application, First Publication Nos. 2000-340955, 2000-353875, and 2001-156456 disclose techniques of forming a capacitor on a substrate on which a semiconductor chip is mounted. In addition, Japanese Unexamined Patent Application, First Publication No. H02-162820 discloses a technique of forming a MOS capacitor on a semiconductor chip.
Since techniques to form a capacitor on a semiconductor chip-mounting substrate entail the capacitor being disposed away from transistors on the semiconductor chip, it is difficult to ensure the response characteristics and high-frequency characteristics of the capacitor. In addition, since a gate film is used as a dielectric layer in techniques to manufacture a MOS capacitor on a semiconductor chip, it is difficult to ensure the capacitance value of a capacitor. Moreover, since transistors cannot be formed in the capacitor formation region, a dedicated occupancy area is needed for the capacitor formation region, which leads to an increase in the size of the semiconductor chip on which a capacitor is formed.